Ch16 - 16.02 - Backing Up and Restoring Data (Back Up Concepts)

Question 1

Full Backup

Answer 1

Include a complete copy of all data

Full backups back up every file that is selected and then clear the archive bit.

Question 2

Incremental Backup

Answer 2

Include all data modified since the last full or incremental backup

Incremental backups back up any files that have changed and then clear the archive bit so that the next backup will not back the file up (unless you do a full backup).

Your restore strategy (known as the order of
restoration) with incremental backups is to restore the full backup and then restore each incremental backup since the full backup. This will ensure that you get the buildup of changes since the full backup.

Pro: incremental backups take less time to back up (because you are getting only changes since the last full or incremental backup)
Con: but more time to restore (because you are restoring multiple incremental backups)

Question 3

Differential Backup

Answer 3

Include all data modified since the last full backup

Differential backups back up any files that have had changes but do not clear the archive bit. Because the archive bit is not cleared, each differential backup will back up all files changed since the last full backup.

The order of restoration strategy would be to restore the last full backup and then to restore your last differential backup.

Pro: less time to restore.
Con: take more time to back up

Question 4

Snapshots

Answer 4

Many organizations use virtualization technology to create virtual machines (VMs) that run their servers on the network. With virtualization software, you can create a snapshot of a virtual machine, which essentially makes a quick backup of its state and configuration. You can then quickly revert to that backup at a later time. One of the drawbacks of reverting to a snapshot is that you lose all changes since that snapshot, so you must be sure you really want to do that.